| The discovery of the Payne effect is of great significance to the study of the dynamic properties of rubber materials,By testing the size of the Payne effect,the interaction between filler and filler in the rubber was characterized,furthermore,the dispersion of filler in rubber was evaluated.The author has different views on this,so take the corresponding experimental methods to confirm it.In this paper,carbon black/natural rubber(NR)composites were prepared by emulsion coprecipitation method,In order to study the effect of carbon black dispersity on the Payne effect in the composites when the molecular weight is the same.By the raw NR,unfilled co precipitation containing sulfide system,co precipitation of carbon black and natural rubber latex and co precipitation of carbon black and natural rubber latex containing sulfide system were thinned at different times,the effect of NR molecular weight and gel on Payne effect of NR compound was studied.As carbon black/NR coprecipitation rubber,with some variety and amount but different dispersion of carbon black,testing the carbon black dispersion and mooney viscosity.Dynamic properties of co precipitation adhesive measured by RPA2000,The results show that the amount of carbon black is not high(15 or less),with the improvement of dispersion of carbon black in rubber,coprecipitation rubber Mooney viscosity decreases slightly,the different(?G')between elastic modulus under low strain and elastic modulus under high deformation decrease,the Payne effect is weakened and the loss factor(tan?)decreases.For the same amount of carbon black and the same variety but different dispersion of carbon black/NR co precipitation which contains vulcanization system,measurement of dispersion and dynamic properties after thermal vulcanization,the results show that with the dispersion of carbon black becomes better,the Payne effect of vulcanizate decreased,and the tan? decreased,compared with non vulcanized carbon black /NR coprecipitation,The elastic modulus increases,Payne effect increases and tan? decreases after vulcanization.Dynamic performance test of NR with RPA,the elastic modulus of NR appeared nonlinear decline phenomenon with the increase of strain were also found,filter out the gel in NR,at low strain,G',?G' and tan? increase compared with before filtration for gel,The results showed that the molecular weight of the sol and gel content had a significant effect on the elastic modulus.NR co precipitation adhesive with vulcanization system that plasticated different time by mixing mill,dynamic properties of rubber and its vulcanizate were tested,the results show that the co precipitation with rubber refining increased,the molecular weight is decreased,G' and ?G' decreased while tan? increased for the plastic rubber and vulcanizates;Compared with the corresponding rubber compound,the G' increased while the ?G' decrease for vulcanized rubber,the results show that the rubber network structure and the entanglement of the chain have contributed to G' at the low strain.Carbon black /NR composite containing vulcanization system was preparatied by emulsion coprecipitation method,which is refined by different times by the mixing mill,the dynamic properties of the rubber and vulcanized rubber were measured,the results show that the increase of the number of times with thin,the ?G' decreases and the Payne effect weakened,Payne effect enhancement after vulcanization.As a result,it can be seen that the Payne effect of rubber material is weakened,not only caused by the improvement of filler dispersion,but also the decrease of rubber molecular weight and the decrease of content of gel,therefore,it is not strict to evaluate the dispersion of filler with Payne effect. |
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